package com.gzsxy.JUC.cas;

import java.util.concurrent.atomic.AtomicInteger;

public class CASDemo {

    //CAS compareAndSet比较并交换
    public static void main(String[] args) {
        AtomicInteger atomicInteger = new AtomicInteger(2020);

        //expect期望 update更新
//        public final boolean compareAndSet(int expect, int update) {
        //如果我期望的值达到了，那么就更新，否则，就不更新,CAS 是CPU的并发原语
        System.out.println(atomicInteger.compareAndSet(2020, 2021));
        System.out.println(atomicInteger.get());


        System.out.println(atomicInteger.compareAndSet(2020, 2021));
        System.out.println(atomicInteger.get());
    }
}
